Ringer volume control



Jm. WW E. RQTHAQKER R INGER VOLUME CONTROL Filed April 25, 1967 IN VE'NTOR m WQWMCWEE R E K C A H T O R 0 E RINGER VOLUME CONTROL 2Sheets-Sheet 2 Filed April 25, 1967 United States Patent 3,487,811RINGER VOLUME CONTROL Eugen Otto Rothacker, Villa Park, Ill., assignorto International Telephone and Telegraph Corporation Filed Apr. 25,1967, Ser. No. 633,616 Int. Cl. Gk 1/36 US. Cl. 116--149 6 ClaimsABSTRACT OF THE DISCLOSURE A plastic damper spring which can be clippedinto place after the assembly of the gongs on a two gong ringer can bepositioned to dampen one, both or neither of the gongs thus controllingthe volume of the ringer or dampening unwanted party-line caused noises.

This invention relates to telephone ringers and more particularly to thevolume controls used with such ringers.

Most of the presently available volume controls used in conjunction withtelephone ringers have a deleterious effect on the frequency response ofthe ringer. For example, one prevalent ringer volume control uses a cammounted gong. When the gong is rotated on the cam it is positionedcloser to or further from the hammer. When the gong is closer to thehammer, the hammer motion is dampened by the gong but the hammer doeshit the gong with greater force thus resulting in a louder ring but amodulated frequency response. When the gong is further from the hammerthere is less dampening but the gong is also struck with less force.

Another frequently used method for controlling the volume of the ring isto dampen the hammer swing directly. This is accomplished by various camdampeners directly abutting the hammer arm to restrict its swing.

Gong dampers 'have been used for dual ringer gongs for selectivelydampening gongs in the tune ringers of frequency selective party linesystems. The gong dampers are advantageous in that they do not adverselyeffect the frequency response of the ringer.

The gong dampers used heretofore have been relatively complicatedassemblies requiring a plurality of parts and only useful either fordesk sets or wall phones. In addi tion, the dampers have requiredrelatively extensive dismantling or the ringer for mounting. Forexample, such dampers have been disclosed in US. Patent No. 2,808,019assigned to the assignee of this application.

Accordingly, it is an object of this invention to provide a new type ofgong damper for use in controlling ringer volume.

A related object is to provide a new ringer having improved frequencyresponse characteristics using the gong damper to effectively preventthe ringer from operating responsive to a related frequency signal infrequency selective partyline systems.

A further object of the invention is to provide a unitary plasticselective gong damper which can be clipped into its operative positionafter the ringer is otherwise fully assembled.

Yet another object of the invention is to provide a unitary gongdampening member that can be used to control the volume of ringers usedeither on desk subscriber telephones or on wall hung telephones.

In accordance with a preferred embodiment of the invention the selectivegong damper comprises a molded unitary plastic member, designed to beremovably spring clipped to a slot in the frame. Centrally located onthe damper is a spring clip arrangement. On each side of the spring clipof the damper is a resilient damping arm which in the mounted positioncooperates with camming surfaces of the ringer frame to selectivelydampen the first gong,

3,487,811 Patented Jan. 6, 1970 the second gong or both gongs. Means forpositioning the dampening means, such as a knob means, is integrallyprovided on the plastic member to extend through a slot in the desk setand thereby enable the manual damping selection. Similarly, an arm witha fork opened toward the gong is integrally provided for capture by thevolume adjustment bar used on wall type telephones. This enables thegong damper position to be varied using the same unity member that isemployed with desk sets.

The above mentioned and other features of this invention and the mannerof obtaining them will become more apparent, and the invention itselfwill be best understood by reference to the following description of anembodiment of the invention taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a top view of a dual gong ringer shown mounted on the bottomplate of a desk set;

FIG. 1a is a pictorial sectional view taken along line 1-1 of FIG. 1;

FIG. 2 is a perspective view of the unitary plastic member comprisingthe gong damper;

FIG. 3 is a view of the bottom of the ringer showing the damper mountedin its operative position;

FIG. 4 is a view looking down on the gongs of the ringer with the dampermounted in its operative position;

FIG. 5 in schematic views a, b and 0 show the three selective positionsof the gong damper;

FIGS. 6 and 7 show how the gong damper is positioned to control theringer volume on a desk set and on a wall set respectively.

In FIG. 1 the ringer which may be of the type described in detail in US.Patent No. 3,172,100 and assigned to the assignee of this invention isshown. mounted to the base plate 12 of a desk set. Only a portion of thebase plate is shown. The ringer is mounted to the base plate by meanssuch as screws 13.

The ringer comprises a frame 14 including a shelf-like integral section15. Rounded disk like sections 16, 17 are provided for mounting the gongassemblies.

Each of the disk-like sections 16, 17 has mounted thereon in a wellknown manner a gong such as gongs 18, 19 respectively. The gongs areshown cut away to disclose a damper mounted to the frame shelf-likesection 15 behind the gongs.

The electromagnetical actuating portion of the ringer comprises anelectromagnet made up of coil 21 and an L-shaped core 22. The core 22 isclamped to the frame 14 by means, such as tabs 23 of plate 24 held tothe frame 14 by screws 26.

The magnetic circuit is completed by a shunt bar 27 that extends from anend of one leg of the L-shape core 22 to the end of the other leg of thL-shaped core 22. The shunt bar 27 is fastened to the frame 12 by screws28, 29.

A permanent magnet 31 abuts the shunt bar at section 32. The magnet actsto magnetically bias the electromagnetic circuit.

A drive rod 34 is fixedly attached to an inverted L- shaped armature 33by any well known means. The armature 33 is attached to the frame 14 byreed spring means. The clapper assembly and the cooperating L-shapedarmature 33 and drive rod 34 are attached to bracket 36 which is fixedlyattached to frame 14 by screws such as screw 37.

FIG. 1a best shows the unique manner of mounting the permanent magnetwhich makes possible an improved frequency response characteristic.

As shown in FIG. 1a the magnet abuts the shunt bar 32. Other than themagnetic attraction therebetween there is no fastener between the shuntbar 32 and the magnet 31.

Means are provided for positioning and holding magnet 31. In greaterdetail, the magnet 31 is properly positioned with respect to armature 33by block 38 which is fastened to the frame 14 with screw 39. The magnetis retained in place by pin 41 which depends from bracket 34 to abutmagnet 31.

As is also best shown in FIG. la the reed spring 42 which supports thearmature 33 is clamped between the bracket 36 and the frame at section14a. The armature 33 depending from the reed spring 42 vibratesresponsive to the actuation of coil 21 with alternating current of aspecific frequency.

Responsive to the energization of the coil, the armature 33 vibratesabout the reed spring 42 and thereby actuates the drive rod 34. Thedrive rod 34 is mechanically tuned to the ringing frequency by varyingthe position of weight 43 located at or near the top of the drive rod34. The drive rod 34 in vibrating causes the clapper assembly comprisingclapper rod 44 and clapper 46 to oscillate and strike the gongs.

The weight 43 and gongs 18, 19 are broken away in FIG. 1 to better showthe inventive gong damper 47 mounted behind the gongs.

'The damper 47 is fabricated of soft, flexible lossy material such asLexan. By the term lossy is meant a substance or material having as acharacteristic property a high loss of energy due to its internalworking or bending responsive to mechanical vibrations, such as: rubber,lead, certain soft plastics, elastomers and the like, for example.

FIG. 2 shows the unique shape of gong damper 47. As shown therein thedamper 47 comprises a main horizontal bar 48. There are projectingportions at each end of bar 48. For example, side 49 of bar 48 isequipped with projecting portion 51 which extends slightly below andforward of the main bar body but in the same plane as the main body.

Side 52 of bar 48 has integrally appended thereto a inverted C-shapedsection 53 designed to clamp and ride on the cam sections of the ringerframe. Section 53 protrudes to the front of the plane of the mainhorizontal bar 48. The protrusion enables section 53 to extend through aslot in the base of the telephone set where it is used for manuallymanipulating the damper 47 to selectively control the volume of theringer.

Immediately above the main horizontal bar 48 is the wall set leverentrapping bar 54. One end of the bar 54 comprises a hook-like section56 which is designed to fit around the volume control lever of wall hungtelephones. The bar 54 is broken away from the main bar 48 at thejoining neck 57 if the damper 47 is used on a desk set.

Means are provided for clipping the damper 47 into place. Morespecifically, immediately below the main horizontal bar 48 is thetransverse bifurcated clamp section 57. The top of the clamp section 58extends back from the bar section 48 and is normal thereto. An L section59 depends from horizontal clamp section 58 to form the opposing side ofthe clip. The resiliency of the material enables the bifurcated clampsection to clip onto a slot in the frame.

The attachment and operation of the damper 47 is better seen in FIGS. 3and 4. Therein is shown the gongs 18, 19. Weight 43 and hammer 46 are intheir normal rest position. The rear of the porch section 15 is providedwith cam section 61, 62 for controlling the proximity to the gongs ofthe portions of the damper that are contiguous to the gong. The cams 61,62 are located to vary the proximity of the sections 49, 52 to the gongs17, 18 respectively, as a function of the horizontal movement of thedamper spring 47.

The cam surface 61 is smoothly rounded and protrudes progressivelyfurther from the gong in the direction away from the center line of theringer. The cam surface 62 on the otheg hand, may be ratcheted withgrooves such 4 as grooves 63, 64. The ratchet grooves enable the damper47 to be moved in steps.

More particularly, the damper 47 clips onto the ringer when theL-section 59 of clamp section 57 is inserted into slot 66 in shelf 15.FIG. 3 illustrates the damper 47 in a broken view to more clearly showhow it is easily attached to a completely assembled ringer. Thprotrusion section 51 rides on cam 61 when the damper 47 is moved to theleft in slot 66. The vertical portion of C- section 53 cooperates withthe detents provided by grooves 63, 64 to stop the movement of thedamper in a step-wise manner. In addition, the vertical portion of theC-section 53 acts as the cam rider to control the proximity of section52 of damper 47 to gong 19. The portion of C- section 53 furthest fromthe ringer may be knurled as shown at 67 to make it easier to manipulatesection 53 which in turn facilitates manipulation of the dampertherewith.

FIG. 4 shows the damper 47 as used in a wall set. More particularly,horizontal section or arm means 54 is shown terminating in claw section56. The claw 56 is shown operatively surrounding lever 68 which is acomponent of a wall type telephone. The section 54 is shown havingWebbing 69 extending between the front of the claw 56 and the mainportion of section 54. The webbing serves as a strengthening rib.

The damper 47 is manipulated in the directions of the arrowheads shownin FIGS. 3 and 4. The position of the damper in detents on ratchetgrooves 63, 64 or at the ends of the cam surfaces determines the volumeof the ring.

More particularly, FIG. 5 shows how the damper may have three positions.FIG. 5a shows the first position. In the first position as illustratedin FIG. 5a the C-section 53 is to the right of the projection of thegrooved cam surface 62. The clip section 57 is at the right hand end ofthe slot 66 and consequently, the cam riding section 51 is to the rightof cam surface 61. As a result both sections 49 and 52 of damper spring47 abut gongs 18 and 19, respectively. Thus, maximum damping is achievedin the position shown in FIG. 5a.

When the damping spring 47 is moved until the vertical portion of theC-section 53 is in groove 64, then the clip section 57 is approximatelyat the center of the slot 66. The section 52 of spring 47 is moved awayfrom its abutting position relative to gong 19 because the cam ridingsurface of C portion 53 cooperates with cam surface 62. This moves thedamping spring 47 away from gong 19 and leaves a space therebetween. Thesection 49, however, still abuts gong 18 to dampen its vibrationsbecause the cam surface 61 has as yet not been reached by cam ridingsection 51. Thus, in position 2 (FIG. 5b) only one gong (19) isdampened.

In position three shown in FIG. 5c the clip section 57 is at the lefthand side of the slot 66. The cam riding section 51 abuts cam surface 51which causes section 49 to move away from abutting gong 18. The verticalportion of C-section 53 rests in groove 63 on cam surface 62. Thus,section 52 is also separated from gong 17. Therefore, neither of thegongs are dampened and the ringer volume is maximized in the thirdposition.

FIG. 6 shows the bottom of base 12 of a desk set with C-section 53protruding through slot 71 therein. The legs of the stand such as leg72, assures that the base is sufliciently removed from the top of anytable upon which the desk set rests to prevent obstruction of section53. To vary the volume of the ringer the subscriber merely picks up thetelephone set and moves protruding section 53 as desired.

FIG. 7 depicts a wall type telephone with the handset removed. Thehookswitch 74 is shown. At the bottom of the telephone lever 68protrudes through a slot, not shown. The volume of the ringer isadjusted when the subscriber moves lever 68 as desired. The movement oflever 68 causes damper 47. to move since claw 56 of section 54 surroundslever 68. Thus, when lever 68 is moved to the left, for example, thedamper 47 is also moved t the left.

It should be noted that the damper 47 is designed to be mounted on theringer after the ringer is completely assembled. This is easilyaccomplished by clipping the damper to the ringer at slot 66. If thetelephone is a desk set, then arm 54 is broken away from horizontalsection 48. The damper 47 of FIG. 3, for example, shows the damperwithout arm 54 while FIG. 4 shows the damper with arm 54.

The ability to mount the damper in a completed assembly means that thedampers and ringers can be separately sold and shipped. That is, anoperating company can purchase ringers and dampers separately and theinstaller can supply a damper if and when the subscriber stationrequires the damper.

While the principle of the invention have been described above inconnection with specific apparatus and applications, it is to beunderstood that this desciption is made only by way of example and notas a limitation on the scope of the invention.

I claim:

1. In combination, a ringer comprising a frame having mounted thereongongs and a gong striking electromagnetic mechanism including clappermeans for striking the gongs, said combination comprising unitary gongdampening structure, means for slidably securing said dampeningstructure to the frame, said dampening structure comprising a horizontalbar made of lossy material, a protruding section integrally appended tosaid bar extending through a slot in said frame enabling slidingmovement of the said dampening structure along said frame, cam ridingmeans at each end of said bar, means at each end of said bar forabutting each of said gongs respectively, said frame including camsurfaces, means for positioning said dampening structure so that saidcam riding means selectively abut said cam surfaces to adjust thecontiguous abutting relationship of said dampening structure to each ofsaid gongs responsive to the position of said dampening structure, clipmeans are provided integral to and dependent from said horizontal bar,said clip means centrally located on said bar and shaped to cooperatewith said slot in said frame for slidably securing said bar to saidringer frame.

2. The dampening structure of claim 1 wherein knob means are provided onsaid bar for manually sliding said bar to position said bar to abut bothone or neither of said gongs.

3. The dampening structure of claim 2 wherein said knob means is at oneend of said bar and comprises said cam riding means.

4. The dampening structure of claim 3 wherein said knob means isC-shaped to connect to said frame, said C-shaped knob depends from thebottom of said bar and protrudes to the front of said bar.

5. The dampening structure of claim 4 including arm means commencing atthe center of said bar and extending parallel thereto, hook meansterminating said arm, and actuating lever means captured by said hookmeans for slidably operating said bar.

6. The dampening structure of claim 5 wherein at least one of said camsurfaces comprises ratchet grooves, and means on said C-shaped knob forcooperating with said grooves whereby said dampening structure ispositioned in a stepwise manner.

References Cited UNITED STATES PATENTS 2,426,068 8/ 1947 Taliaferro.

2,808,019 10/1957 Houdek ll6l49 2,878,464 3/1959 Ham et al ll6l49 X2,929,351 3/ l 960 Spitler 1 16149 3,127,602 3/1964 Russo et al. 340-401X 3,172,100 3/1965 Houdek 340-401 3,370,567 2/1968 Rieth.

LOUIS R. PRINCE, Primary Examiner D. M. YASICH, Assistant Examiner U.S.Cl. X.R. 188-4

